Abstract

A rapid, reliable and sensitive online method was proposed to determine sulfide ion in tannery effluent based on the combination of methylene blue spectrophotometry and automatic reference Flow Injection Analysis. In acidic media with Fe3+, without any process of H2S absorption or sample pre-distillation, sulfide could be determined directly by the automatic reference FIA function of an automatic metallic elements analyzer using p-aminodimethylaniline dimethylaniline (C6H4•NH2•N (CH3)2•2HCl) as colour developing reagent. Under the optimal conditions, the linear ranges of this method were 0.01 – 0.25 and 0.20 – 2.16µg/ml; the detection limit was 4.642ng/ml, and relative standard deviations were 2.5% (n = 8) for a 3 x diluted tannery effluent. Asatisfied result was achieved with the proposed method to determine the sulfide in tannery effluent, and then the range of recovery percentages was 96.0 – 104.0%.